class A { 
int x = 10; 
void show() { 
System.out.println("A: " + x);
} 
} 
class B extends A { 
int x = 20; 
void show() { 
System.out.println("B: " + x); 
} 
} 
public class Test16 { 
public static void main(String[] args) { 
A a = new B(); 
a.show(); 
System.out.println("A: " + a.x); 
System.out.println("B: " + ((B)a).x); 
} 
}